Blindstitch sewing machine



Nov. 11 1924.

c. w. MUELLER 1514'713 BLINDSTITCH SEWING MACHINE Filed June 28. 19123 7 Sheets-Shed l -Illl-l E; Mijas W/lfllor (Ruim ELMMWVWM 3 2 m .l. 1u. t 7. e e n Aw M w 1m 4 I l S f. l m m W dw m m A f m H 8 ,u m m w M u w 2 Y M S muv M H W m d C. w m fl. m Mw. wf T iw. wm 3 flillli( N .Nwi i Mw a4. l. 2 mw @H ll 1 |l 2 ,.1515 w MNHN @L @W @4 H M8 wn 0 /4 WUU M` f4 w 5 x M w1 Nov. l1 1924 v 1,514,713 c.rw. MUELLER BLINDSTITCH SEWING MACHINE Filed June 28, 1918 7 Sheets-Sheet 3 Nav. 11 1924. l '1,514,713

C. W. MUELLER BLINDSTITCH SEWING MACHINE Filed June 28. 1918 7 Sheets-Sheet 5 New. M 3924 1,514,713 C. W. MUELLER BLINDSTITCH SEWING MACHINE- Filed June 28, 191B 7 Sheets-Sheet 6 Nov. ll 1924.

C. W. MUELLER y lBLINDSTITGH `SEWING MACHINE.y

' Filed June 28. 191 7Sheets-Sheet 7 Patented Nov. 11; 1924.

asians CHARLES W. MUELLER, OIE' ST. LOUIS, MISSOURI, LSSIG'NOR, BY MESNES ASSGNMENTS,

TO ARBETTEB EELILNG-y MACHINE COMPANY,

A CORPORATION' OF MAINE.

BLINDSTIT CH SEWNG MACHINE.

Application. filed June28, 1818. Serial No. 242,355.

To all wiofmf t may] concern.'

Be it known that l, CHARLEs 1V. MUEL- Lnn, a citizen of the United States, residing in the city of St. Louis and State of Missouri, have invented new and useful lmprovements in Blindstitch Sewing Machines, of which thefollowing is a specification. f

My invention relates to improvements in blind-*stitch :sewing ,mechines; and has for its general object to provide an improved machine of the vibrating-needle type; in which the needle may be Acaused to move laterally, to change its path of reciprocation, between successive thrusts, for the formation of two rows of stitches. More spe-y cilically my invention provides an improved machine for felling the edge of an overlying layer of fabricto the body or base layer and it consists in the novel features of construction and arrangement hereinafter described and claimed. The combinations and arrangements of parts wherein my invention is embodied may best be understood by reference to the accompanying drawings wherein- Fig. 1 is a side elevation, with parts in section, of a complete machine forming one embodiment of my invention;

Fig. 2 is a front view of the stitching head and associated parts. principally in elevation, with parts in section;

Fig. 3 is a 'vertical section on line 3-3 of Fig. 2;

Fig. f1 is a fragmentary section on line L1-l of Fig. 3;

Fig. 5 is a horizontal section on line 5-5 of Fig. 2; n

Fig.-6 is a sectional view on line 6-6 of Fig. 5;

yFigs. T, 8 and 9 are perspective views showing fragments of the stitchforming mechanism in successive progression of operating positions;

Figs. 10,111,` 12 and 13 are sectional ele- `rations showing portions ofthe feed mechanism in successive operating positions;

Fig. 1&1 is a detail section on line lit-111 of Fig. 10;/ i

Fig lis a detail of the-slide-nut con struction of the feed;

Fig. 16 is an elevation, with parts broken of the underside of the machine;

away,

1T is a plan detail of the clamp Fig. plate;

Fig. 18 is a section therethrough;

Fig. 19 is a diagram illustrating the seam made by the machine;

Fig. 20 is a detail of the plunger and stop-lever;

Fig. 21 is a section on line 21-21 of Fig. 1.

l have illustrated my present invention as embodied in a machine comprising a frame 25 having a lower arm 26 that carries the worlehandling mechanism; a post 27 that houses the vertical shafting; and the upper arm 28 that supports the main shaft and has at its end the arcuate bearing arm 29 in which is mountedr the stitching` head 30. The stitching head is so constructed that the stitching center; or point of cooperation of the needle with the work is7 at approximately the center of the arc of arm 29 and the head carries at its lower extremity a presser foot 31 for cooperation with the stitch-forming, feeding, and work-handling mechanisms. The upper portion of the head-carried mechanism is housed in a cover 32. i

The specific work for which my machine is designed, in the particular embodiment shown; is substantially that accomplished by the machine shown in U. S. patent to John G. Lewis, No. 862,830.

ln the present machine the head-shaft 35 (Fig. 3), driven by a gears-couple 36 from the mainL shaft 37; Lcarries the counterbalanced crank arm 38; the wrist pi-n 39 of which operates a link e0; the lower arm of which (Fig. it) engages `the wrist pin 41 of the needle arm l12 which is slidingly pivoted between its ends, has its wrist pin slidable through the link 40, and atits forward end carries the needle 43. This train ,of mechanism imparts lengthwise reciprocation to the curved needle to make one reciprocation during each revolution of the headshaft; and leaves the needle-arm free to be vibrated laterally.

The needle bar is vibratable along its pivotal axis through a range that is variable by lili that extends through the center of the pivot' 46. This spindle makes threaded engage ment with a knurled nut 49 for retraction of the head 47 against the tension of a spring 50, which is interposed between the .bottom of a recess in the pivot 46 and the enlarged part of the spindle 48, and the spindle is prevented from turning with the nut as by a feather 5l. The sleeve 45 is engaged by a shifter' lever 53 which is pivoted at its upper end as at 54 and is acted on by soring 55. that tends to throw the needle bar toward the adjustable spindlehead 47 and so serves to maintain a roller 56 on the shifter lever in contact with a cam 57k which constitutes the postively moved part for vibrating the needle. rlfhe shaft 5S for this cam 57 extends through the rear wall of the head frame SOand is driven from the head-shaft through an upright connecting shaft 59 by means of appropriate spiral gear couples 60 and 6l (Fig. 3) which rotate the camshaft in one-toetwo relation to the head shaft. The cam 57 is cut to present diainetrically opposed arcs of different radius joined by smooth intermediate curves7 and the radius-difference of these arcs measures the maximum vibration of the needle. The arc of larger diameter throws the needle to its non-variable or leftward limit of throw and the arc of lesser diameter peri iits the needle bar to move laterally under the influence of spring 55 to such extent as is determined by the adjustment of the spindle 48. f

The stitch-forming mechanism of course includes suitable thread-guiding, controlling, and take-up devices, and some form of loop-taker which (in a lock-stitch machine as herein shown) may be a suitable rotary hook 62 carrying a second thread bobbin in conventional manner. This rotary hook 62 isr driven from the vertical head-shaft 59, and is located close to the bacl: wall of head 30, above the presser foot. but these parts require no` specific description.

'In the form shown the needle strikes from the front of the machine rearwardly at some suitable angle to the line of feed, such angle being etermined to suit particular conditions of work to be performed, and in this instance being shown as about twenty degrecs.

The needle in its reciprocation travels over the upper surface of the presser foot 3l, that is rigidly secured to the lower portion of the stitching head and that is provided with an opening 65 through which the work, fed alongk the underside of the presser foot may be presented to the operation of the needle.

The present construction of machine is particularly well adapted for the felling of a raw or folded edge of an overlying layer of material to a baselayer by means of two connected rows of stitches, one of ywhich engages only the underlying or base layer and the other of which engages only the overlying layer or layers of material. For this purpose the overlying layer of materfal may well be presented to the needle through the opening 66 with the on-feeding portion (i. e. the portion approaching the stitching` point under the influence of the feed) of the overlying material traveling above the surface of the presser foot and the on-feeding portions of the base material traveling beneath the presser-foot, so that the needle,

on its reciprocation in one (the rightward one) of its twopaths may enter under the edge of the overlying layer of material to strike diagonally upwardly through suoli layer alone, while on its other reciprocation (along the leftward line) the needle may enter and emerge from the upper surface of the base layer only, the latter being elevated through the opening 66 to receive the needle-thrust, as by means of a plunger 68. rllhe off-feeding (already stitched) portions of the worlr pass below the presser foot. both as to the base and overlying layers, and of course appropriate work-holding means is provided in conjunction with suitable feed mechanism, to eect proper handling of the fabric.

The presser foot shown, see Figs. 7 and 14, is cut away as at 70 on the rightward side, to leave open, as at 71, a chord of the work-opening 66 of the presser foot, the anlgle between the openings constituting a lifting point 72, the edge of which is pref* erably slightly upturned as at 73. ln front of, or toward the operator with respect to, the lifting point 752 an edge-guide in the form of elevation 7 4 is provided, this guide being arranged to direct the edge of the itil overlying layer of fabric., as it is being fed,

along a line that intersects the leftward path of reciprocat-ion of the needle well baclr vof t-he stitch-forming position. so that the needle will not engage the guided edge when making this leftward thrust. but may engage the edge when the needle has been vibrated to its alternative. rightward path of reciprocation. j

The presser foot is thinned as at 75 along the area over which the needle moves. and is 'i also slotted onparallel lines as at 76 to receive the feed dog, to be described.,v and it is preferably provided with a leaf-spring eX- tension 77 that serves as a needle guard to preventinjury7 to the operators lingers, and as a guide to facilitate rapid insertion of the work. This guard, attached to the bridgethe present machine I have provided a plunger-adjustment novel in structure and functioning; In association with the plunger proper I provide an adjustable element that will coact with the presser foot (indirectly, by acting directly against the underside of the clamp member 3 which in turn works against the goods underlying the presser foot) close to the work-opening and will function to check the rise of the plunger positively at different elevations according to the thickness of the goods-layer or layers encountered by the adjustable element. This element which I designate the plunger-stop I preferablyy construct as an angular lever 135, pivoted as at 136 to the plunger, having its upper end slightly below aid in line with the plunger end or tip, and arranged to coact with the underside of thc clamp-member 83, and having its rear end connected with the means for effecting the stop-adjustment or variation of relative position as between the tip of the stop and the tip of the plungerproper. Thus the stop lever may be a stamping with a circular pivot head'lll? struck thereon to engage a receptive recess 138 in the plunger-lever 120, the stop lever takingI shape corresponding with the plunger lever at its front end, and near its rear end being deflected to run alongside of the plunger lever. Its rear end is slotted as at 139 and engages a, crank portion lll-O of the shaft 121 which is mounted rotatably and provided, at the front of the machine with a knurled head 141. Manifestly when the stop lever encounters sufiicient resistance to upward movementit holds the plunger against further rise and spring 124 yields to permit bell-crank 123 to complete its throw. It will be apparent that adjustment may be made while the machine is running.

In the operations of the 'machine the work, consisting, say, of a base rlayer A of fabric which may be of relative heavy material, an overlying layer of 'fabric B, presenting a raw or folded edge Z2 to be felled to the `base layer, is inserted in the machine with the edge of the overlying layer along the line defined by the edge guide 74 of the presser foot, the portion of this edge that is ready to be stitched lying; over the guiding point 73 and being thereby raised somewhat above the level of the base layer. In this condition the work is fed to the machine by the overhead feed that, in virtue of its positive engagement with the upper surfaces of both layers, advances them equally, substantially eliminating slip between the layers. When, now, the stitching is in progress, with the transverse range of needle vibration appropriately adjusted, the needle, effecting its stroke on the leftward path of reciprocation, will enter and emerge from the upper or stitching surface of the base layer A of material, the latter being bent in a node through the presser foot opening by means of the plunger 68 which rises before the needle reaches its point of penetration and recedes when the needle has properly passed into and out of the goods. The usual cooperation of the thread-carrying needle with the second-thread-carrying hook mechanism results in the formation of a lock stitch slightly diagonal to the direction cf feed and local to the base layer of the fabric. Then after the needle has retracted and a feed movement has taken place the needle makes its second stroke along its rightward path of reciprocation so that its point enters under lthe raised edge of the overlying layer B and emerges from the upper side thereof back from the edge, and, in cooperation with the loop-taking mechanism, lays a second stitch on a line parallel with the rst, but local to the overlying layer of material. This process continues, the tension exerted on the threadsk drawing the superimposed layer down upon the base layer and rolling its edge, if folded, so that the needle thread, the runs of which lie wholly on the surface of thebase fabric and substantially or completely concealed, and only the runs of bobbin thread n which pass over the edge of the overlying layer B are exposed to view.

llilhile I have herein described my invention in one working embodiment only, it will be apparent that its novel features may be varied in details of structure and arrangement without departure from my invention within the scope of the appended claims.

I claim:

1. In a sewing machine for blind-stitching, the combination with an apertured presser-foot, stitch-forming means working above said presser-foot, plunger means working below and through said presserfoot, work-feeding means, and work-clamping means below said presser foot comprising a work-plate having a work-contacting surface.r and a clamp-bar carried by said work plate, yieldable relative thereto, and having a work-contacting surface.

E2. In a sewing machine for blind-stitching, the combination with a presser-foot. stitch-forming mechanism above said presser-foot and including a needle. feeding means arranged above and working through said presser-foot and having laterally separated feed-points between which the needle works, and a .work-holding clamp below said presser-foot cooperating with the underside thereof and having respective surfaces presented to both feed-points, the portion of said clamp presenting a surface to one feed point being yieldable with. reference' to the portion of said clamp that presents a surface to the other feed point,

3. In a sewing machine for blind-stitching, the combination with an apertured rennais wall of the Apresser; foot, extends forward beyondftlle left portionpf theffootand` upward about concentrically with the needlepath.

In the `specific construction shown fthe work is fed wholly by an overhead feed mechanism comprising a yoke-shaped feed dog 80, the two arms 81, 82 of which depende-on opposite sides `of the presser foot opening to straddle the paths of needleyreciprocationv and work through the slots vpivot `stud J86,l .(see Figs. 2 and 15.) `has a stem pivoted in a' slideblock 89 that is vertically slida'blefin slot 90 of *any arm ,9,1 that is norma-lly stationary in the stitching Y frame, v and kthe block may; be clamped in Apivoted in the frame any position of vertifcl adjustment by a nut v92en'gagin'g the threadedv stud 93 and bl'oclr 89jsogthat the vertical position of the stud may bevaried with consequent adjustment of the vfeed length. 4The arm 91 is .pivoted as at 93 to the head frame, vnormally Vheld againsty :displacement '.by a spring latch 94 engagingv an opening in the arm to {iX-it rigidly. Byidisengaging" the latch thearm may be swung upwardly and.,y toward the operator, to give access topartsbelow and rear of the feedl mechanism,especially the hook, which is directly in rear thereof, for convenience for changing bobbins and the like.; "The cyclic operation of the feed dog is shown in Figs. 10 to 13..-

` The work holdingclamp 83 is carried by a post v100 vthat extends intothe lower arm 26which is mounted ona slide 4block 101 (Fig.l 1) verticallymovable in vguides in said Vframe arm, and .normally held -ink elevated position by a str-ong leafjspring 102 which bears on the frame projection 103 and is adjustable as to tension by an adjusting screw 104': taking through a frame projection 105 and engaging a nut 106 mounted on the base ofthe spring 102. A depressing lever 107 l at 108 serves, when lifted bya lr'nee-lift,ll(not shown) to depress theclamp plate to facilitate insertion of the 10i-k l y 1:' u y. l, The `-clainp .niember83 is preferably mounted ina y'olfey pla-,te 110 e which has lateral,A rearwardly-extending ears lllkin which is pivoted the' clamp block proper whichgis :thereby so sustained that it has a considerable capacity for tilting either its forward orrearward edge downward toyield for the passage of'unevenv thicknesses of material under the presser foot'. The block is provided with an aperture ,112, to accommodae the plunger 68, and at that side of said erst-ture (t1-ly ilgltward. Sdlf sro-w15@ construction shown) v `along .which the greatest thickness of goods is intended to passgin the usual working of the machine, theclainp .n

block is provided with a supplemental'clamp bar 1141. rThis bar is located in a recess 115 in the blockv and is mounted on al stop screw that takes loosely through a hole in the bottom fof the Yrecess and engages the `harto-define, ad- 1, justably, itsmaximum elevation labove the block 88. front and rear of the screWare springs 117 that hold the bar 'normallylevel and protruded somewhat above .the block,

but that give the bar the capacity .to be de.-

pressed bodily and tilted on itsipost or screw ne. i .f `rlflormally the clamp member 83A holds the fabric layers firmly against the undersidefof the presser foot, as need be to accommodate the pressureof the feeddog, tilting fore and, aft.under.unbalanced pressures such as these caused by the passage of cross seams or other. inequalities yielding bodily somewhat ai,

ofthe work through the machine, this tilting of thev entire clamp block being supplemented by a yielding and tilting yof the snpplemental bar 114 in the clamp block under the influences of crossy seams or otherV inequalities that are localto .the thicker ..or

multiple layer Zone of the w-orkthat passes over .y the righthand side only of the clamp plate. .l y

Theplunger, 68,' for the vclass of work particularly intendedto be handled, maybe 4 a flat, narrow vertical strip extendingacross thedirection of feed and located'tacross, the leftwa-rd path of reciprocationfonly, .of vthe needle. This plunger may bean upstanding linger integral with a plunger. lever 120 at i 1.

isv pivoted on atransverse shaft. 121 wit iin the frame. The plunger iscaused to rise on every alternate reciprocationof the needle-,- i. e., itsstrolres in the leftward coursefby means actuated from the main shaft. Thus a bell-crank lever 123, pivoted on orc-0ncentrically with shaft 121 has its yforwardlyprojecting armarranged to. overlie the plunger lever and connected by retractible spring i124 with the plunger is positively depressedand yield.- ingly elevated. rlhe pendant `'arm 125- of such lever 123 is connectedby link` y127yyith alever 128. 16) the remote, end vvof lio the plunger-levery so that E which is pivoted at 129 to the -frame and I,the 3; 3

movable extremity of which bears aroller 130 that `runs in the track of a face-cam 131 mounted on afvertica-l shaft 132 driven from the main shaft by a suitable one-to-two gear couple 183. I y I. o,

It is important for `many..sewing opera tions, including the class of worlrhereinbefore suggested, thatA the plunger elevation shall depend somewhat upon the .thickness ofthe goods4 and shallneyer rise aboveV a level adjustable but predetermined, and in iz's presser-foot, stitch-forming means working above saidjpresser-foot, work-bending means for presenting work throughsaid presserfoot-opening, work-feeding means, and clamping means below said presser-foot comprising a vyieldingly supported clampplate and a supplemental clamp-bar yieldingly supported by Saidclamp-plate.

a. In a sewing machine for blind-stitching, the combination with an apertured `points on opposite sides of the two paths of reciprocation of the needle, and a work-v holding clamp `below the presser-foot cooperating with the underside thereof and having surfaces presented to ,bothA lfeed points,the portion of saidelamp presenting a surface to oney feed point being yieldable with reference to the portion ofi'said clamp thatv presents ymaterial to" 4theother feed' K. point.

6, In asewingwmachine for blind stitch- `Ming, the combination with a` presser-foot,

stitch-forming mechanism above said presser-foot including -a needlearrangedto vibrate between twowpaths of reciprocation and a loop-taker cooperating therewith, feeding means arranged above and working through said presser-foot and having feed points on opposite sides of the t-wo-paths of reciprocation ,of the needle, andra work-holding yclamp below the presser-foot cooperat- `ing'with the `underside thereof and having surfaces presented to both feedpoints, the

portion of said clamp presenting a surface to one feed point being tiltable with reference to the portion of said clamp thatpresents material to the other feed'point.

7. In `a sewing-machine for blind-stitching, the combination with a presser-foot,

l stitch-forming mechanism above said presserating with the under side thereof and having surfaces presented to both feed points,

, the portion'of said clamp presenting a surface to one feed-point 'being bodily depressible and'ti'ltable' fore-and-aft with reference to the portion of said clamp that presents material to the other feed point.

8. A` blind-stitch sewing-machine comprising in 'combination a presser-foot having a plunger opening, free at one side thereof for the 'passage of multiple layers'of material past said opening, some layers below said presser-foot and others over the front'portion of thev presser foot, and having feed point apertures, feeding 'meansabove the presser-foot having points working through the presser-foot apertures, a clamp plate below the presser-foot having two surfaces opposed to said feed points, one of Vsuch i surfaces being yieldable with respect to the other surface, a plunger arranged for co-` operation with said presser-foot opening to present through for cooperation with the material only that layer or layers of fabric which passes below the presser foot; stitchforming mechanism comprising a needle and rloop-taking means working above the presser-foot and means to vibrate and reciprocate said needle; and means to actuate said plunger during alternate reciprocation 1of' said means.

9. llVork clamping means for cooperation with the presser-foot of a blind stitch sewing machine comprising a yieldingly supported yoke, a clamp plate pivoted to'tilt fore-and-aft in said yoke, and a supplemental bar mounted on said clamp plate and arranged toyield for bodily depression and for fore-and-aft tilting with respect to said clamp plate.

10. In a blind stitch sewing machine, a stitching head having forwardly extending sides, a presser foot at the bottom of said stitching head, stitch-forming means above said presser-foot including a bobbincarrying'hook near the rear of said head, p a feed member supported above and 'working through said presser foot and having a bar extending in front of said hook and past the end of said needle arm bearing, said' arm being shiftable forwardly away from the 'hook to free the bobbin for ready removaljand latch means normally maintaining said feed arm in the first stated position.

ll. In a blind stitch sewing machine, a frame comprising an upper arm carrying stitch-forming mechanism, such stitch-forming mechanism including a rotary hook mounted near the rear of said frame and a curved reciprocating needle cooperating therewith, a presser foot carried by said arm below the stitch-forming mechanism, work holding means below said presser foot cooperating therewith, Aand feed mechanism comprising an overhead feed bar normally disposed in front of said hook, means for imparting feeding movements to said bar, and means permitting bodily displacement of said feed bar to give access to said hook.

12. In a blind stitch sewing machine, a frame comprising an upper arm carrying stitch-forming mechanism suoli stitch-forining mechanism including a rotary hook mounted near the rear of said frame and a curved reciprocating needle cooperating therewith, a presser foot carried by said arm below the stitch-forming mechanism, work holding means below said presser foot cooperating therewith, and feed mechanism comprising a vertical feed bar, means swiveling said feed bar between its ends, means for'imparting four-way motion to the upper end of said feed bar, a pivoted supporting arm for said feed bar swivel, and latch means normally positioning said pivoted arm and operable to free said arm for pivotal displacement of the feed bar swivel to move the feed bar away from the hook.

13. In a blind stitch sewing machine, a frame comprising an 'upper arin carrying stitch-forming mechanism, suoli stitch-form- 'ing mechanism including a rotary hook mounted near the rear of said frame and a curved reciprocating needle cooperatingtherewith, a presser foot carried by said arm below the stitch-forming mechanism, work holding means below said presser foot cooperating therewith, and feed mechanism comprising an arm 91 pivoted to the frame and slotted, a latch 94 for normally holding said arm against pivotal displacement, a swivel 86 vertically adjustable in said slot, a feed bar 85 slidable through said swivel, feed points on the lower end of said bar, and means pivotally connected with said bar for imparting four-way movement to its upper end.

14. In a blind-stitch sewing machine, the combination of a presser-foot having a work opening; stitch-forming means on one side of said presser-foot; a work-clamping member on the other side of said presser-foot, and having an opening; plunger means, working through said presser-foot and clan'ip-member openings; stop means for positively limiting the movement of the plunger toward the work, said stop means coacting with the clamp member for determination of its stopping position therefrom; means for vibrating the plunger to elevate it yieldably and depress it positively, a main. shaft for supplying power to the moving parts, and positive connections between said shaft and the plunger-vibrating means.

15. In a blind-stitch sewing machine, the combination of a presser-foot having a work-opening, stitch-forming means on one side of said presser-foot, plunger means on the other side of said presser-root, and adlever, a stop movable with said plunger lever arranged to cooperate with the presserfoot and adjustable to vary its position with respect to the end of the plunger, means for actuating said plunger lever, and means eX- tending to the exterior of the machine for adjusting said stop means with respect to the plunger. Y

17. In a blind-stitch sewing machine, the combination of a presser-foot, stitch-forining mechanism on one side of said presser foot, plunger means working through said presser foot, comprising a pivoted plunger lever, a stop movable with said plunger lever arranged to cooperate with the presser-foot and adjustable to vary its position with respect to the end of the plunger, yielding means for lifting said plunger and stop means, and means for adjusting said stop means with respect to the plunger.

18. In a blind-stitch sewing machine, the combination of a presser-foot, stitch-forming mechanism above said presser-foot, workclamping means below said presser-foot, plunger means working through said presser-foot, comprising a pivoted plunger-lever, a stop-lever pivoted to the plunger-lever having one end arranged to cooperate with the presser-foot and yadjustable with respect to the end of the plunger, and means for adjusting said stop lever upon said plunger.

19. In a blind-stitch sewing machine, the combination of a presser-foot, stitch-forming mechanism above said presser foot, a plunger-lever having an end arranged to work through said presser-foot, a stop-lever pivoted to the plunger-lever, and having an end arranged to coact with the presser-foot, and means accessible from the exterior of the machine for adjusting said stop-lever with respect to said plunger-lever, and means for adjusting said plunger-lever.

20. In a blind-stitch sewing machine, the combination of a presser-foot, stitch-forming mechanism above said presserfoot, a

plunger-lever having an end arranged tok work through said presser-foot, a stop-lever pivoted to the plunger-lever, and having an end arranged to coact with the presser-foot, and means accessible from the exterior of the machine for adjusting said stop-lever with respect to said plunger-lever, and means for yieldably elevating and positively depressing said plunger-lever.

21. In a blind-stitch sewing machine, the

lll)

combination of a presser-foot having a ,i

work-opening, stitch-forming mechanism on one side of said presser-foot, a plunger col operating with said presser-toot opening, a stop for cooperation with the presser-foot adjacent said plunger-opening, adjustable with respect to said plunger and movable therewith, means for actuating said plunger, and means accessible from the exterior of the machine for adjusting said stop with respect to said plunger.

22. ln a blind-stitch-sewing machine, the combination of a presser-foot, stitch-forming mechanism above said presser-foot, a plunger-lever working through said presserfoot, a shaft wherein said plunger-lever is pivoted having an eccentric portion, means accessible from the exterior of the machine for rotarily adjusting said eccentric portion, a stop-lever pivoted to said plunger-lever and having a portion engaging said shaft eccentric whereby rotation oi said eccentric adjusts the stop with respect to the plunger, and means for raising and lowering said plunger.

23. In a blind-stitch sewing machine, the combination of a presser-toot, stitch-forming means above said presser-toot including a needle, vibratable for reciprocation in two paths, and work-presenting meansy below said presser-foot comprising a plunger working through the presser-toot and arranged to cooperate with the needle at one path only of reciprocation of the latter, means for raising said plunger on appropriate excursions of the needle, and adjustable means carried by said plunger cooperating with the under side oi' the presser-foot to limit the throw of the plunger.

24. In a blind-stitch sewing machine, the combination oi a presser-foot, stitch forming mechanism on one side of said presserfoot, plunger means on the other side of said presser-foot having a portion to work through the presser foot and a portion to coact with a portion of said presser-toot to limit the throw of the plunger, one of said coacting portions being adjustable, and means Jfor actuating said plunger.

25. In a blind-stitch sewing machine, the combination of a presser-foot having a work opening, stitch forming means on one side of said presser-foot, plunger means on the other side of said presser-foot having a portion to present the work through said presser-'toot opening and a portion to coact with a portion of said presser-foot to limit the work-bending throw of said plunger, and means for actuating said plunger yieldably to effect its said throw.

26. ln a blind-stitch sewing machine, the combination of a presser-foot having a workopeninO", stitch forming means on one side of saidD presser-foot, plunger means on the other side of said presser-foot havingaportion to present the work through said presser-ootopening and a portion to coact with a yportion oi said-presser-ioot to limit'the `work bending throw of said plungerfand means for actuating said plungeryieldably to eiiect its said throw and positivelyy to ettect its depression.

27. In a blind-stitch sewing machine, the combination of a presser-foot having a. work opening, stitch forming means on one side oi' said presser-foot, plunger means on the other side of said presser-foot having a portion to work through said presser-foot opening and a portion to coact with a portion of said presser-foot to limit the work-bending throw of said plunger, one oi said coacting portions being adjustable to vary the limit of said throw, and means for vibrating said plunger arranged yieldably to effect its said throw.

28. In a blind-stitch sewing machine, the combination of a presser-foot having a work opening, stitch forming means on one side oi said presser-toot including a needle vibratable for reciprocation in two paths, and work presenting means on the other side of said presser-foot comprising a plunger working through the presser-foot and arranged to cooperate with the needle at one path only of reciprocation of the latter, means for raising said plunger on appropriate excursions of the needle, said pressertoot and plunger having coacting portions to limit the work-bending throw of the plunger, and means for adjusting one of said portions to vary the limit of said throw.

29. In a blind-stitch sewing machine, the combination of a presser-foot, stitch-forming mechanism on one side of the presserfoot, yieldingly mounted work-clamping means on the other side of said presser-foot; plunger means on the last said side arranged to work through the clamping means and presser-foot and having a portion to coact with a portion of said work-clamping means to limit the work-bending throw of the plunger, one of said portions being adjustable; and means for actuating the plunger.

30. In a blind-stitch sewing machine, the combination of a presser-foot having a work opening; stitch forming means on one side of said presser-foot; and work presenting means on the other side of said presser-foot comprising an apertured clamp member and a. plunger vibratable through the clampmember and presser-foot; a stop member adjustably carried by the plunger arranged to coact with said clamp-member to limit the projection of the plunger through the latter; means for actuating the plunger and means for adjusting said stop-member.

31. ln a blind-stitch sewing machine, the combination oi a presser-'toot having a work opening; stitch forming means on one side of Said presser-foot; Work Vpresenting means on the other side of said presser-foot oomprisng an apertured clamp-member and a plunger vibra-table through the clampmember and presser-foot; a stop member acljustably carried by the plunger arranged to ooaot With said clamp-member to limit the projection of the plunger through the latter; means for actuating the plunger; and means accessible and operatable While the machine is in operation, for adjusting said stop member. p

' CHARLES W. MUELLER. 

